Gear mechanism



Oct. 7, 1930; c. H. HARDIE 1,777,490

GEAR MECHANI SM Filed Dec. :25, `1929 Patented Oct. 7, 1930 CHARLESFH. Hannie, or soUTH GATE, cALIroRnIA einen MEcHnNisiyi VApliicatim filedv December :23,v i929. serial No.v 416,052.

This invention relates `to a gear mechanism and relates more particularly to a speed reduction device.V Itis a generalfobject of the .invention to .provide a practical, eEective speed reduction device. f Itis another. obj ect of the inventionto provide a speedy reduction device that has a maX- imum speed reduction ratio for a minimum number of Working parts.

It is another obj ect of the invention to proyvide a idevice of the character mentioned Whereinv a highr speed, or drive pinion drives a freely rotatable gear which carries a'planei tary pinion meshingfivith afiXed gear and a tion includes, generally, a housing 10, `a drive `shaft'or high speed shaft lldrivenibyfthe loW speed or driven gear having'a different number of teeth than the 'fixed gear.

Itgisanother object ofthe invention'to Vprovide a speed reducer of the character mentioned in which a split .planetaryu pinion is carried by the freely rotatable' geanwhich has a part meshing With a fixed gear andi a partnieshing With the driven gear, or low speed gear.

25 Itis another object ofthe invention to `providel a Vspeed reduction device ofthe character mentioned particularly `adapted to be usedin connectionivith an electric motor.

Other objects and features of iny inven tionwill'be bestand more fully understood from the following detailed description of vtypical forms and application of the invention, throughout e VWhichV description refer-V i ence is had to the Vaccompanying drawings, 135 in which:

Fig. lis a vertical detailed sectional view of the device provided by this invention illustrating it in connectionivith atypical electric motor.l Fig. 2 AisV afverptical detailed sectional .view `tallienfas indicatedfby line 2%-2 on Fig.` 1.c Fig. 3 is an enlarged: vertical sectionalzvieivtaken as .indicated by line 3-3 f on Fig. 1. Figlis an enlarged vertical sectional vievv taken as indicatedfon line on Fig. 5 is an enlarged vertical` Vde- Fig. 1. e f tailedsectionalvievv taken substantially as indicated byline-,5&5 onfFig. `2.v Fig. `6 -is a vertical detailed sectional vievv ofl another .50 formfioffthe inyention. Fig. Pisa vertical by the planetary pinions 14 and 16.

in the opening 26. i

detailed sectional view taken as indicatedby line 7--.7 on Fig. 5.

The speed reduction device vprovided by the present invention is' applicable tovarious f usesand may be used in connection with various sources of power. rIn thefollowing detailed description I Will 'describe the invention in connection `With a typical `electric motor. vIt is to be understood,howe,ver, that the invention is not to' be limited to .'thelpan `60 ticular form or applicationabout to be described, but it is to be taken as includingany features or modifications that mayfallfwithin the scope of the claims.

The device provided by the presentinlvene5 electric motor E and carrying adrive pinion 12,'a Afreely rotatable internal gear `if13 Within the housing 10 drivenby thepinin 12, two planetarypinions 14 and 16 carried by the-gear 13, a fixed orstationary gear 15 about Which the planetary pinions operate, and a driven gear or low speed gear 17 driven `ns The housing 10 isprovided to encase the other parts of the device and may be of any suitable construction., In the form of the linvention illustrated in the Vdrawings, the housing l'includes'a cylindrical bodylpor-so tion 18 and end plates 19 and 20clo'sing the ends of the body portion 18. The end plates 19 and 20 may be provided with annular recesses or grooves 21 to receive the end'sfof the body portion 18. `The endplates 19 and ,g5

2O inay be provided With suitablebase or supporting flanges Theend plate 19 is provided With a central outwardly .project ing boss'23 havinga central bearing opening '24. In the particular case illustrated, a.90

bracket 25 is mounted on'theouter sidegof end `plate .19. The bracket 25 .supports the motorl E and carries the linotor sov that the motor shaft: 11 extends parallel with thecentral axis of the body. `The shaft ,11 extends through an'opening 26 in the endplate 19 to Vproj ect` into the housing 10.

"Axsuitablef bushing 27 may `be` provided The` lend plate 20 Vis*providedn.iith. accu-100 tral outwardly projecting boss 28. The boss 28 is provided with a comparatively large cent-ral opening 29. A fixed shaft 30 is carried in the opening 24 of the plate 19 and extends through the housing and through the opening 29. The shaft 30 may be fixed to the end plate 19 in any suitable manner; for example, it may be keyed to the plate 19 by the key 32.

The freely rotatable gear 13 is mounted within the housing 1() to freely rotate about the shaft 30. The gear 13 is preferably an internal gear so that the device may be embodied in a compactstructure. vA suitable bushing or bearing 33 may be provided to "mount the `gear 13 on the lsha-ft 30. In accordance with the invention, the gear 13 is mounted adjacent the inner side of the end plate 19 and is driven by the high speed pinion 12. An inwardly projecting flange V35 isv provided on the peripheral portion 34 of the gear 13. 'Iwo longitudinally extend- "ing sockets or openings 36 are provided in the flange 35. The sockets 36 are preferably diametrically opposite and are comparativelylarge, extending the entire depth of the flange 35 and being open at the outer and inner sides of the flange 35.

The fixed gear 15 is mounted on the shaft adjacent the inner side of the internal gear 13. The gear 15 may be held against rotation relative to the shaft 30 by a suitable key 37. The gear 15 is of slightly less diameter than the inner side of the flange 35 so that it is arranged Withinthe flange. The fixed or stationary gear 15 is provided tooperate or carry the pinions 14 and 16 and to cause thev pinions to rotate to drive the driven gear 17.

The planetary pinion 14 vis rotatably mounted in one of the sockets 36 to operate over t-he fixed gear 15. rlhe pinion 14 is rotatably carried on'aistud 38 extending through the peripheral portion 34 of the internal gear and extending through the socket 36. vThe stud 38 extends in parallel alignment with the stationary shaft 30 and car-Y ries the pinion 14 so thatit effectively meshes Vwith the teeth on the periphery of the fixed 17. The-pinion 14 is comparatively long so or stationary gear 15 .and the'driven gear 'that it extendsbeyond the edge ofthe fixed gear 15. y

In accordance with the invention, means are provided for retaining the pinion 14 on thestud 38'and for effectively supporting the outer end of the stud 38. A retaining plate 140 is mounted on the outer side. of the flange 35 and extends completelycover the socket 36. The plate 4() isprovided with an opening 41 which passes the end portion of the stud 38. A suitable key 42 may extend Y transversely through the end portion of the stud 38 to engage the plate 40 and hold the ystud against longitudinal movement.

opposite the pinion 14. The planetary pinion 16 is mounted in the socket 36 in the same manner that the pinion 14 is mounted. A st-ud 52 is carried by the internal gear 13 and extends longitudinally through the socket 36. The pinion 16 has two portions 53 and 54 at which the teeth are in different rotative positions. In practice it is desirable to forni the pinion 16 in two parts or sections 53 and 54 fixed together against relative rotation by pins 54a or other suitable means. Section 53 meshes with the teeth of the fixed or stationary gear 15 while section 54 meshes with the teeth of the driven gear 17. The sections 53 and 54 of the pinion 16 may be retained on the stud 52 by a plate 58 attached to the flange 35 and extending over Ythe socket 36. The plate 58 is provided With an opening 60 passing the outer end portion of the stud 52. The plate 58 operates to support the stud 52. A key 61 may extend 'transversely' through the end portion of the stud 52 and engage the outer side of the plate 58. It Will be obvious that there may be more than two planetary pinions provided on the gear 13 Where the device is to transmit heavy loads or drives.

The driven gear 17 is rotatably mounted on the fixed shaft 30 adjacent the stationary gear 15. The gear 17 has an effective diameter the same as that of the fixed gear 15 and has an axially extending hub 43 which extends through the opening 29 of the end plate 20. In practice, a bushing 44 may mount the gear 17 on the shaft 30. The driven or low speed gear 17 is driven by the pinions 14 and 16. In accordance with thc invention, the gear 17 has a different number of teeth than the gear 15. It is preferred that the variation in number of teeth on the gears 14 and 17 be slight, say, for instance, one or twoteeth. v The pinions 14 and 16 operated or rotated by the teeth of the fixed gear 15 rota-te a certain number of times with each revolut-ion of the internal gear 13. f

It will be seen that by providing thefgear 17 with a different number of teeth than carried by the gear 15 that the gear 17 will rotate relative to the stationary gear .'15. It is to be further understood that the direction in which the low speed gear 17 is driven depends upon' the relative number of teeth of the gears 15,and 17, that is, it depends upon whether thelow speed gear 17 has a greater or less number of teeth than the gear 15. Y y

A bushing 45 may be'provided between the exterior of the 'hub 43 and the walls'of the opening 29. vSuitablemeans may be provided for connecting the low speed gear 17 l man-1.90

with the part to be driven or operated. In the drawings I have illustrated a section 50 of a coupling keyed on the outer end of the hub 43 by a key 51.

In Fig. 6 of the drawings I have illustrated a form of the invention similar to that described above, except that it embodies two phases or two cycles of speed reduction. In this form of the invention the freely rotatable internal gear 7 0 is driven by a high speed pinion 71 and carries two planetary pinions 72 and 73 similar in construction to the planetary pinions 14 and 16 described above. The pinions 72 and 73 mesh with a fixed gear 74 and drive a first driven gear 76. The gear 76 carries at its periphery two planetary pinions 77 and 78 similar to theV pinions 72 and 73. The pinions 77 and 78 engage a fixed gear 79 and drive a second driven or low speed gear 80.

It is believed that the operation of the device provided by the present invention will be understood from the foregoing detailed description. It will be seen that the internal gear 13 rotates slower than the pinion 12. 'Ihe pinions 14 and 16, by meshing with the fixed gear 15 and the driven gear 17 operatel to shift thev driven gear 17 very slightly upon each rotation of the free gear 13. The amount of movement of the driven gear 17 relative to the fixed gear 15 depends upon the respective number of' teeth of these two gears. Further, the direction in which the driven or low speed gear 17 is operated relative to the fixed gear 15 depends upon whether the driven gear 17 is provided with fewer or more teeth than the stationary gear 15. The pinions 14 and 16 being diametrically opposite `operate to equalize the forces transmitted to the driven gear. It is to be particularly noted that the device embodies but few parts and gives a very great reduction of speed. The retaining plates 40 and 58 prevent the studs 38 and 52 from being forced out of alignment and are a feature of the invention.

I-Iaving described only a typical, preferred form of my invention, I do not wish to limit myself to the specific details set forth, but wish to reserve to myself any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims Having described my invention. I claim:

1. A device of the character described including, a housing, a shaft extending through the housing and stationary relative to the housing, an internalgear freely rotatable on the shaft, an axial flange on the periphery of the internal gear having spaced sockets, a drive shaft extending into the housing, a pinion on the drive'sliaft adapted to rotate the internal gear, a gear fixed on the stationary shaft adjacent the internal gear, a driven gear rotatable on the stationary shaft and the driven gear.

having a differenti number off teeth "than the -xed gear, Y and: aA planetary pinionV mounted vv2.' A speed reducing -device including, a

rlliousing,`la shaft extending into the housing and held stationary relative to the housing,

gear. inthe housing freely rotatable on the shaft, means for rotating the said gear, a gear fixed on the shaft, a driven gear rotatable on the shaft and havinga dierent number of teeth than the fixed gear, a stud carried in the peripheral portion of the firstmentioned gear and extending into a socketin the first-mentioned gear, a pinion rotatably mounted on the stud within the socket and engaging the teeth of the fixed gear and the driven gear, and means retaining the pinion on the stud. i

3. A speed reducing device including, a housing, a shaft extending into the housing and held stationary relative to the housing, a gear in the housing freely rotatable on the shaft, means for rotating the said gear, al gear fixed on the shaft, a driven gear rotatable on the shaft and having a different number of teeth than the fixed gear, a stud carried in the peripheral portion of the first- Inentioned gear and extending into a socket in the first-mentioned gear, a pinion rotatably mounted on the stud within the socket and engaging the teeth of the xed gear and the driven gear, and means retaining the pinion on the stud and supporting the end portion of the stud.

4. A speed reducing device including, a housing, a shaft extending into the housing and held stationary relative to the housing, a gear in the housing freely rotatable on the shaft, means for rotating the said gear, a gear fixed on the shaft, a driven gear rotatable on the shaft and `having a different number of teeththan the fixed gear, a stud carried in the peripheral portion of the firstmentioned gear and extending into a socket in the first-mentioned gear, a pinion rotatably mounted on the stud within the socket and engaging the teeth of the fixed gear and n ing diametrically opposite openings, a gear j adjacent the internal gear fixed to the shaft, a driven gear adjacent the fixed gear rotat-` able on the sha-ft and having a diferent num- 'ber of teeth than the iixed gear, axial studs on the internal gear extending into theopenings, and a pinion on each of the studs engaging the teeth of both the xed gear and the driven gear, and lmeans retaining the pinions on the studs and Supporting the 'ends of the studs. v

In witness that I claim the foregoing I have hereunto subscribed my name this 8th day of I\Tove1nber,` 1929.

CHARLES H. HARDIE. 

